A World War II fighter plane flown by a veteran stunt pilot has crashed into the ground near spectators during an air race, killing three and injuring more than fifty people.

The plane, piloted by 74-year-old Jimmy Leeward, spiralled out of control without warning and appeared to disintegrate upon impact. Bloodied bodies were spread across the area as people tended to the victims and ambulances rushed to the scene.

The P-51 Mustang, a class of fighter plane that can fly at speeds in excess of 800km/h (500mph), crashed into a box-seat area in front of the grandstand about 4.30pm local time, race spokesman Mike Draper said.

Officials told that the crash was caused by mechanical problems.

Stephanie Kruse, a spokeswoman for the Regional Emergency Medical Service Authority, told The Associated Press that emergency crews took a total of 56 injury victims to three hospitals. She said they also observed a number of people being transported by private vehicle, which they are not including in their count.